Diagnosis of the primary lesion (MTC)
The diagnostic algorithm for suspected malignancy is strictly divided into two key stages.
At the preoperative stage, the pathomorphologist and endocrinologist rely on three criteria:
- Presence of a high concentration of calcitonin in peripheral blood.
- Specific cytological picture of thyroid cancer obtained via fine-needle aspiration.
- Detection of a high level of calcitonin in the washout obtained directly from the puncture needle.
At the postoperative stage, final verification is carried out. Confirmation of the diagnosis of MTC is based exclusively on histological examination data of resected tissues, supplemented by immunohistochemical (IHC) analysis results.
Treatment control and functional monitoring
A comprehensive approach is required to reliably assess the disease progression dynamics and therapy efficacy. Regular monitoring of thyroid, liver, kidney, and pancreatic function is indicated for the physician.
The monitoring protocol includes:
- Laboratory methods: complete blood count (CBC), biochemical profile, coagulogram, and urinalysis.
- Instrumental and morphological base: liver ultrasound and (if indicated) fine-needle aspiration biopsy of the liver. The obtained biopsy specimen is sent for thorough cytological and histological examination to rule out secondary involvement.
Secondary lesions and jaw tumors
Thyroid cytology is closely linked to the assessment of metastasis. The thyroid gland, along with the breast, prostate, lungs, stomach, uterus, and kidneys, is a frequent source of secondary metastatic tumors in the jaw.
Overall, malignant jaw tumors account for 1.5% to 3.0% of all malignant neoplasms. According to their origin, jaw carcinomas are classified into:
- Primary (central): localized within the bone thickness, developing from epithelial cell rests of Malassez.
- Secondary: arising from the contact spread of the process from the mucosa to the bone tissue.
- Metastatic: the result of tumor cell seeding from other organs.
Differential diagnosis and confirmation of the diagnosis
Tumor differentiation requires specific techniques, among which the leading ones are: cytological examination of the obtained scraping, direct tumor puncture, and open biopsy.
When the neoplasm is localized on the palate, a differential diagnosis must be made with cylindroma, mucoepidermoid, and mixed tumors of the minor salivary glands. When the alveolar ridge mucosa is affected, chronic inflammatory processes and epulis are ruled out first.
Morphology and clinical presentation: Carcinoma and Sarcoma
The histogenetic classification of jaw tumors divides them into epithelial (carcinoma, malignant epithelioma, cylindroma, odontogenic carcinoma) and connective tissue (sarcomas). Among carcinomas, keratinizing squamous cell carcinoma leads in frequency, followed by non-keratinizing squamous cell carcinoma, poorly differentiated carcinoma, and adenocarcinoma. Among sarcomas, osteosarcomas dominate; chondrosarcomas, fibrosarcomas, and myxosarcomas are diagnosed less frequently.
The clinical presentation is diverse and depends on the histological structure, localization of the primary focus, and routes of spread.
| Characteristic | Jaw carcinoma | Jaw sarcoma |
|---|---|---|
| Epidemiology | More frequently men aged 40–60 years | Young and middle-aged individuals (10–40 years) |
| Growth pattern | Grows slower, but infiltrates tissues faster | Rapid growth, sharp deformation. Proliferates into tissues more slowly |
| Ulceration | Disintegrates quickly, turning into an ulcer | Ulcerates late |
| Metastasization | More often to regional lymph nodes | More frequently metastasizes to distant organs |
For quick memorization of the origin of jaw carcinomas, use the PPM mnemonic: P — Primary (from rests of Malassez), P — Secondary (contact with mucosa), M — Metastatic (incl. from the thyroid gland).
Class and exam questions
Which examinations confirm the diagnosis of thyroid cancer before surgery?
At the preoperative stage, clinicians focus on a high concentration of calcitonin in the blood, the presence of a characteristic cytological picture of cancer, and high levels of calcitonin in the needle washout.
Which pathologies are tumors of the alveolar process differentiated from?
When the alveolar ridge mucosa is affected, the clinical and cytological picture is differentiated primarily from epulis and chronic inflammatory processes.
What is the main difference in the growth pattern of carcinoma versus sarcoma?
Carcinoma grows slower, yet it tends to early ulceration and rapid infiltration of surrounding tissues. Sarcoma, on the other hand, exhibits rapid growth with bone deformation, but ulcerates and invades soft tissues at later stages.
How is the patient's condition monitored in the postoperative period?
Monitoring includes laboratory control (CBC, biochemistry, coagulogram, urinalysis), liver ultrasound, and monitoring of kidney, pancreatic, and thyroid functions. Fine-needle aspiration biopsy of the liver is performed according to strict indications.
What else to study on this topic
- Criteria for immunohistochemical (IHC) examination in thyroid tumors
- Morphological characteristics of the epithelial rests of Malassez
- Cytological differentiation of mucoepidermoid and mixed salivary gland tumors
- Features of performing fine-needle aspiration biopsy of the liver when metastasis is suspected
- Histogenesis and diagnosis of odontogenic carcinoma
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